A porous carbon with excellent gas storage properties from waste polystyrene

In this paper, we describe the synthesis and gas adsorption properties of a porous carbonaceous material, obtained from commercial expanded polystyrene. The first step consists of the Friedel-Craft reaction of the dissolved polystyrene chains with a bridging agent to form a highly-crosslinked polymer, with permanent porosity of 0.7 cm3/g; then, this polymer is treated with potassium hydroxide at a high temperature to produce a carbon material with a porous volume larger than 1.4 cm3/g and a distribution of ultramicro-, micro-, and mesopores. After characterization of the porous carbon and determination of the bulk density, the methane uptake was measured using a volumetric apparatus to pressures up to 30 bar. The equilibrium adsorption isotherm obtained is among the highest ever reported for this kind of material. The interest of this product lies both in its excellent performance and in the virtually costless starting material.